Keyhole lock



Nov. 20, 1928.l

W. LOGG KEYHOLE Loox Filed March 9, 1927 Patented Nov. 20, 19278.

UNITED STATES PATENT oEFicE.

WENDELL LOGG, OF LOS ANGELES, CALIFORNIA, vASSIG-NOR TO INDEPENDENT LOCK I COMPANY, or FITCHBURG,

MASSACHUSETTS, A CORPORATON.

KEYHOLE LOCK.

Application filed March 9, 1927. serial No. 173,867.

This invention relates'to improvements in keyhole locks, and more particularly to locks of the type shown and described in Patent Number 1,554,443, issued to me on September 22, 1925.

Among the objects of my-invention ris to provide a plug, or, stoppel, which is key controlled, for insertion in the keyhole ofa lock whereby to prevent unauthorized access to the lock.

`A further object is to provide a construction of keyhole lock which may serve for locks having relative wide range of dimensions. 4

j And a still further objectis to provide a keyhole plug, or stoppehwhich will be automatically locked against withdrawal upon insertion in a keyhole; whichr is so designed as to be employed in locks wherein the spacing of the walls of the lock casings varies, even to the extent of including a portion of the length of the catch of the plug, and to provide a lconstruction which is simple Vand economical and lends itself to multiple or quantity production.

My improvements consist in the novel construction, arrangement and combination of parts as hereinafter fully, clearly and concisely described. definitely pointed out in my claims and illustrated by the accompanying drawing (1 sheet) inwhich* Fig. 1 is a side elevation'of a keyhole lock, constructed in accordance with my invention with thelocking catch thereof in locking position so that the device may not be withdrawn from a door and lock therefor, without a proper key, fragments only of the door and door lock are shown and which are in section. A

Fig. 2 is a transverse section, taken on the yline 2.-2 of Fig. 1.

Fig. 3 isa transverse sectional elevation taken on the line 3-3 of- Fig. 1, showing the locking catch within the keyhole 'of the casving of the door lock and in locked position.l 3, showing F ig. i isa View similar to Fig. ,Y the catch as turned in the keyhole of the lock casing.

Fig. 5 is a longitudinal sectional elevation showing the catch in locking position. y

Fig. 6 is a transverse sectiontaken-v on the line 6 6 of Fig. 5, showing the securing means between the stem and cylinder.

Fig. 7 is a view similar to Fig. 1, showing, the lock partiallybroken away and in section,

and showing the catch as turned, by a'key, to released position.

Fig. 8 is a plan view of the my Akeyhole lock.

Referring more specifically to the drawing A designates generally a door, which as .is

common, has a lock mortise 10 from which lead openings 11-11 extending from opposite `sidesof the mortise through the door; and B designates an ordinary door lock havingthe usual casing side-walls 12-12 in each of which is a keyhole slot 13, registering with the openings 11 in the door.

The device of my invention embodies an element 'C constructed as a unit and consisting of a cylinder 14, a stem 15, and a collar 16 formed between the cylinder and stein. The cylinder has a longitudinal key-'slot 17 and tumbler pockets 18 formed wholly to one side of the collar 16, and the stem^ is formedy as a tube with a cavity 18 which is intersected Aby opposed aligned slots 19-19,fthroughi which slotsis extended a catchgQO arranged in the cavity and pivoted on a pinQl. The catch 2O is formed on one end with a camface 22 extending vertically adjacent to the stem portion of pivotal support of the catch on the pin 21.

and the body of the catch QO'eXtendine; from the side of the pivot pin 21 opposite the cam Q2 is formed with parallelv upper and lower margins a and Z) providing the catch with a major length having a dimension substantially equal to the diameter of the stem 15 so that when the catch is moved to a position substantiallyparallel with the stem its major length projecting from the pin will lie bodily within Athe stem as shown by dotted lines, in Fig. 5; the outer end portion of the catch being extended on the under side thereofbeyond the uppermost slot 19 the stem to provide a motion limiting shoulder' 23. AA wall portion o is formed on the outer end of the catch extending beneath the shoulder 23 and from the margin Y), the lower edge of which wall portion normally lies within the slot 19.

This wall portion will be projected through j ever that when the catch is disposed in its depressed positiony as shown in dotted lines in ig. 4, the major portion of' its length represented by its margins c and b will l-ie wholly Within the stern and that when the catch isdepressed either wholly or partially the lower portion oi' the catch contiguous to the pin 21 will not project beneath the stem l5.

' This construction ot' the catch 2() is important and advantageous in that it permits the use of the device in a door lock in which the side walls-12 of the lock are so close together that when the device is positioned in the keyhole the inner end portion of the catch will extend into the lock opening 13 as shown in Fig. 1, as will later be described. Within the cavity18 is a yielding pressure means consisting of a bearingor ball 24 which seats against the Y -carn 22, a spring 25,and a bearing 26 preter- 15 at the end of the slot 19 so that the outer portion of thecatch 2O will project from the cylinder 15 in the locking position as shown in Fig. 5. l

A cylindrical casino'` 28 formed with a radially extending tumiblerhousing 29 is ex-` tended telescopically over the cylinder 14 toV cover the tumbler pockets 18 and afford a housing in which the cylinder 14 is turnable. The housing 29 is formed with a plurality of bores 32 in each of which is placed a tumbler 33a follower 34, and a sprnr 35 which bores are closed after assemblage ci the parts therein by plugs 36 driven into the outer ends of the bores in rictional engagement therewith. Extending rearwardly from the tumbler housing 29 is a web 3T which projects beneath f thecylinder 15 and is adapted to he extended into the keyhole opening 13 in one of the walls of the lock casing. The upper edge of the web isformedwith a lug 38 projecting alongside a. transverse notch 39. In assembling the device the cylinder 14 is inserted in the bore of the casing28`from the rear end of the latter with the lug 38 positioned in the slot 17 which slot extends through the collar 16 as particularly shown in Fig. 8. The lug 38 may be thus brought to a position past the collar 16 so that the latter will extend into the notch39 whereupon burrs 40 areformed on the margins of the slot 17 where the latter `passesthrough the collar 16 as shownin Fig.

6, so as to inhibit withdrawal of the lug 38 through the slot.` The collar 16 then being positioned in the notch 39 the cylinder 14 and casing' 28 will be held against longitudinal movement relatively to each other with the l cylinder 14 turnable in the casing. This manner of assembling the cylinder 'Withinthecasing is advantageous in that it obviates the'use of extraneous securing devices and enables intei-connection of the cylinder and casing with great facility. y

vIn the operation of the invention, after first locking the door lock inthe usual manner with its key and withdrawing the key, the stern 1.5 is inserted in the keyhole together with the casing 28 and tumbler housing 29; the stem 15 being passed throughthe door lock casing such distance as to permit the catch 20 to snap into place behindthe first wall of the casing as particularly shown in Fig. 1. The casing 28'and tumbler housing 29 will then lill the keyhole so as to prevent` insertion of keysor other instruments into the" door lock. The device will then be securely held in the keyhole against turning and against removal. y

To efectremoval of the device, a proper kev 41 is inserted in the key slot 17 to bring the tumblers 33 to their unlocking position as y is common in tumbler locks whereupon the cylinder 14 may be turned to dispose thecateh 20 in a downwardly extending positionas shown in Fig. 7 so thatit maybe withdrawn L through the keyhole.

In event the side walls 12 of the doorlock casing are disposed in such close proximity that when my device 1spla`ced in its lookin 0 position Within the keyhole, the catch 2 0 will extend into thekeyhole opening 13 as shown in Figs. 1 and 3 no obstruction to rotation of the stem 15 will be afforded by reason of depression of the catch asvmight then occur, as the lower edge of the lcatch will remain within the boundaries of the stem 15 as shown in Fig. 4. This is of material advantage over any construction in whichjdepression of the catch would cause the lower portonthereof `to extend into the parallel sided portion d vrof the keyhole opening 13, asshould this occur turning of the stem 15 to an unlocking position would be inhibited, thereby preventing withdrawal of the ld evice from `the key-hole by operation ofthe key 41.

I claim l.` In a lock of the class described, a catch whose major length portion comprises substantially parallel sides, a cam formed at one end of said major portion and a motion limlol',

lll)

iting shoulder opposite said cam` and offset ried by said element, a. spring actuated latch pivotally carried by the stem Vfor normal pro- ]ec'tion radially therefrom and whose major length portion may be swung to a position `Whony within the Stem.

3. A device ofthe class described comprisi ing a keyhole stoppel consisting of a substan-` tially cylindrical portion and a radially exY tending web said web having a plurality of being extended throgh the slot in said collar bores formed therein to receive look tumblers, and said collar being 'burred to prevent movel0 -a look cylinder rotatably mounted in said rment of the said Web portion axially relative stoppel, a stem extending from the loek cyl? to the stem.

inder, a. spring actuated catch carried by the In testimony whereof, I have affixed my stem, a collar between said cylinder and stem, signature.

there being a key Slot formed in said cylinder and through said collar, a portion of said Web WENDELL LOGG. 

